In International Publication No. WO2012/038161 (referred to as Patent Literature 1 hereinafter), a technique of inspecting a current sensor is described. Patent Literature 1 shows a method of inspecting a current sensor that measures a battery current as to whether the current sensor normally operates or not. FIG. 1 is a diagram showing FIG. 1 of Patent Literature 1. In Abstract of Patent Literature 1, there is a description that “During a precharge phase (32) which begins at a time (34) at which at least one electrical component (20, 22, 24) is connected to a battery (100) and during which the electrical component (20, 22, 24) is precharged by a precharge current, at least one measured value provided by the current sensor is compared with an expected current value determined from an expected temporal profile of the precharge current.”.
FIG. 2 shows a configuration of a current sensor that is capable of measuring a direct current and an alternating current at the same time. A current sensor 900 comprises a core 910, a magnetometric sensor 920 and a main unit 930. The core 910 is made of a magnetic material (such as iron) and has the shape of a ring with a gap. The magnetometric sensor 920 is disposed in the gap of the core 910 and measures a current passing through a plane 911 surrounded by the core 910 by measuring a magnetic flux inside the core 910. A Hall element is commonly used as the magnetometric sensor 920. The main unit 930 displays and outputs the measurement result.